"This tube has a range of five miles, and will penetrate a foot of lead. I have killed animals with it by breaking up the haemoglobin in the blood. By special adjustment, its effects would be fatal at even greater range. It might be set to break the body proteins into the split protein poisons--there are a thousand ways it might kill a man, quickly or by hideous lingering death. "Used in war, the Vernon Ray would not only kill men, but destroy or ignite such useful chemicals as fuels and explosives. It would destroy vegetation and food supplies. In fact, it would make war impossible, and it is my hope that it will end war altogether!" "But what if the wrong fellow gets hold of it?" He nodded to a safe at the wall. "Plans locked up there. And nobody knows about it. Even if someone had the plans, he could hardly secure the large quantities of thorium required without attracting attention." I thought of the raid on the gas mantle factory. "I mean to turn it over to the American government pretty soon, but I hope to make another development. Ordinary heat and light waves set up molecular disturbances in matter; in fact, heat is merely molecular vibration. I hope to discover a frequency in the spectrum that will stimulate atomic vibration to such an extent as to break down the electronic system. Objects upon which such a ray is directed will explode with incredible violence. In my earlier experiments with _Vernonite_, the molten alloy in the tube, I almost had a catastrophe from the atomic explosion of the electrode. It would have blown El Tigre off the map! The radioactivity of thorium is slight; I must increase it vastly. The adjustment is delicate." He let me look into the apparatus. It was plainly electrical. There were motors, generators, coils, transformers, mirrors and lenses in a lead housing, vast condensers, and a huge vacuum tube which seemed to have a little crucible of glowing liquid for the anode. Back of it was a great parabolic reflector which must have sent out the beam of destruction. "The idea of atomic force as a d-d-d-d-destructive agency is not new," he went on, again almost too enthusiastic to talk. "The sun is thought to ob-ob-ob-obtain its boundless energy from the process of atomic disintegration, and m-m-m-m-m-men of science long since agree that any instrument using intra-atomic energy would be a t-t-t-t-terrible weapon!" CHAPTER III Clouds of Doom Suddenly a red shape flashed over the great glass dome above us. In a moment I heard Bill call out, "Hey, Doc, comp'ny's come!" Dr. Vernon and I hurried out of the room. He paused to double lock the door behind him, and we went down to the hall. We found Bill and Ellen both waiting at the front door, each holding a 30-30 carbine. "There's one of the red ships out there!" the girl cried. Eager and flushed with excitement, she was very beautiful.